Printing viscose on textile fabrics.



UNITED STATES PATENT OFFICE.

EMILE AUGUSTE FOUBNEAUX. OF MANCHESTER, ENGLAND, ASSIGNOB EQ CALICOPRINTERS ASSOCIATION LIMITED, OF MANCHESTER, ENGLAND.

PRINTING VISCOSE ON TEXTILE FABRICS.

I0 Drawing.

To all whom it may concern: I 7

Be it known that I, EMILE AUGUSTE Form- NEAUX, Ph.D., a citizen of theUnited States, residing at St. Jamess Buildings, Oxford streetManchester, in, the county of Lancaster, England, have invented new anduseful Improvements in Printing Viscose on Textile Fabrics, of which thefollowing is a specification.

In printing viscose on textile fabrics it has heretofore proveddifiicult to produce regularly and uniformly a film capable of resistingmechanical strain. Rubbing strains especially tend to break that portionof the film which lies on the surface of the fiber, and as it isprecisely onthat portion of the film that the print mainly depends forits effect it follows that the desired effect is to a considerableextent lost. If the viscose be used as a carrying and fixing medium forinsoluble mineral matter this defect becomes even more perceptible,especially if the mineral matter employed has little or no mechanicalafiinity for the fiber.. In order to resist such strains the film mustbe strong, elastic and flexible and it must adhere well both to thefiber and to the mineral matter, if any. It must moreover be capable ofre sisting the action of the chemical and mechanical agents to which thefabric may subsequently be subjected in the ordinary course ofmanufacture. Films consisting essentially of sound cellulose answerthese requirements reasonably well' provided the amount of viscosedeposited on the fabric be suflicient to form a substantial film andprovided the degree of penetration of the viscose into the fabric becorrectly regulated. If the film is to be produced by printing it mustin addition to the above requirements give a perfect and sharpimpression or mark. The production of such an impression involv'es theuse of a printing color of suittable consistency, applied by a printingroller not too deeply engraved, so that the amount of the viscosesolution deposited on the fiber can only be comparatively small. Itfollows therefore that the use of relatively concentrated viscosesolutions is necessary if a substantial film is to be obtained.

Correctly prepared viscose solutions of normal composition and suitablethickness are excellent printing colors as long as they are fresh, butthey are barely concentrated enough to produce a substantial film withSpecification of Letters Patent.

' Application filed March 7, 1918. Serial No. 752,740.

Patented Feb. 24, 1914.

any but the heaviest patterns and they soon deteriorate by becomingthicker and less fluid, in technical parlance short, as polymerizationtakes places and leads to less soluble viscoses. In order to retardpolymerizatlon and improve the printing qualities of concentratedsolutions it has been found advantageous to use viscose solutionscontainmg a material excess of alkali, preferably caustic alkali. Afterprinting the fabric with viscose it must be submitted to certaintreatments for the purpose of fixing the viscose, that is ofregenerating cellulose. This can be accomplished by a variety of means,such as treatment with concentrated solutions of suitable acids orsalts,exposure to dry heat or to steam, or even by leaving or exposing thegoods until fixation takes place spontaneously. \Vith one exception allthese methods involve exposure of the cellulose compounds tothe'simultaneous action of air and alkali. The destructive action ofalkalis on cellulose in the presence of air is well known and it istherefore not surprising to find that the film ultimately obtainedsometimes contains considerable proportions of bodies other than soundcellulose and consequently falls short of the technical requirements.The only alternative method of fixing viscose, (viz., treatment withconcentrated solutions of suitable acids or preferably salts) isunfortunately not as satisfactory for the present purpose as it is forsome other purposes, for instance the manufacture of artificial silk.Viscose prints fixed by this wet method are apt to lose mfich of theireffect and smartness by the slight runnin due to the action of the waterbefore fixation takes place; the fabric is soiled by the sulfur andsulfur compounds precipitated thereon. and a lengthy and rather tryingtreatment is necessary for the purpose of removing these impurities aswell as the excess of precipitating agent.

The underlying principle of my invention consists in preventing thedetrimental action of the alkali during the dry fixing processes byneutralizing a considerable part of the alkali soon after printing andbefore any material destruction of the cellulose can take place. Forthis purpose I impregnate the fabric before printing with a solution ofa suitable material capable of neutralizing the required proportion ofthe alkali of the viscose solution, and dry. I then print the preparedfabric, which should preferably be calendered for the purpose ofobtaining a smooth and hard face, with a suitable viscose solution,preferably containing an 5 excess of alkali for the reasons statedabove.

After printing, I fix the viscose by exposure to dry heat, steaming, orspontaneou decomposition, but preferably by a combination of theseseveral means.

Materials capable of neutralizing a portion of the alkali of the viscoseare obviously acids and their equivalents, such as acid salts, esters,and the salts of weak or volatile bases. In order to be suitable for myprocess such substances must not have any detrimental effect on eitherthe fabric or the viscose under the working conditions. It is alsodesirable that they should have a gentle and gradual action so as not tointerfere with the necessary degree of penetration of the viscose intothe fabric and that they should be readily removed from the fabric bythe subsequent washing. Substances such as fats, which though capable ofneutralizing alkali act so slowly under my working conditions thatneutralization does not take place soon after printing and before anymaterial destruction of the cellulose can take place, are not suitablefor my purpose.

Several of the materials which I use are essentially the same as used inthe known wet fixing process, but the two processes differ essentiallyin the mode of application and in the "urpose to which they are applied.In the known rocess the fabric is passed through relative y concentratedsolutions of the said materials after printing, whereas in my processthe fabric is impregnated with relatively diluted solutions of the saidmaterials and dried before printing. In the known process the saidmaterials are used for the pur ose of bringing about complete fixation,w ile in my process they are applied for the purpose of neutralizing theexcess of alkali and only contribute to the fixation of the viscose tothe extent that less alkaline viscoses fix more readily, but I dependfor complete fixation on ex osure to dry heat steaming, or spontaneousecomposition. In the known processthe said mate rials must be applied inexcess for the purpose of decomposingthe viscose rapidly and completely.In my process it is on the contrary essential to avoid completedecomposition of the viscose which would lead to less satisfactoryfixation and to the occurrence of "anost .of the objectionable featuresof the wet process described above, and for this reason the proportionof the said materials incorporated into the fabric must be carefully Iregulated. It is also desirable to select materials having a gentle andgradual action so as not to inter ere with the necessary degree ofpenetration of the viscose into the fabric. Apart from the materialsabove specified the solutions which I use for the purpose of impregnatinthefi'ser may advantageously contain 0t er substances such as glycerin,hygroscopic salts, sultable thickening agents, etc. The viscosesolutions used for printing purposes may contain suitable additions suchas insoluble mineral matter, pigments, coloring matters, preferably ofthe vat dye class, etc. The addition of glycerin to the printing colorsis not desirable but ma at times be-necessary for the purpose of xingcoloring matters.

I append one example by way of illustration but- I wish itto be clearlyunderstood that I do not confine myself to the particular materials orsubstances specified or to the proportions stated as the same may bevaried or modified according to requirements.

Example: The fabric is slop padded witha solution containing four percent. ammonium sulfate and dried. It is then calendered. The fabric soprepared is subsequently printed'with a suitable viscose solution, 0. g.a solution containing ten per cent. l

cellulose in the form ofviscose and five and a half to seven per cent.total alkali calculated as caustic soda (NaOH) to which may be addedeight to ten per cent. of suitable mineral matter, such as china clay,etc. The

printed fabric is then dried and subsequently pased through the shortcontinuous steamer technically known as ager for say three minutes atabout two hundred and ten degrees Fahrenheit for the purpose of fix 4'ing the viscose. The fabric may then 'be washed at once or if necessarythe fixation may be completed by allowing it to lie for a day or-twobefore washing.

\Vhile the. underlying principle of my in vention may be fairl obviousits application is to the best of my knowledge novel and undoubtedlyuseful and it could not be foreseen a priori that the desired technicalefi'ect-reliable production and fixation of a strong elastic andtenacious film capable of withstanding mechanical strains-would bebrought about by these means, es cially as it was not improbable thatthe e ect of the contact between the viscose and the-neu tralizingmaterial would be to prevent fixation of the cellulose film on thefabric.

- I declare that what I claim and desire to secure by Letters Patent inthe United v States is 1. The herein described method of printingviscose on text-ile fabrics which consists in impregnating the fabricbefore rinting with a solution capable of neutra izing a considerablepart of the alkali soon after printing and before any materialdestruction of the cellulose can take place, drying the impregnatedfabric, printing with a viscose solution preferably containing an excessof alkali and finally fixing the viscose by any of the usual methods,substantially as described.

2. The herein described method of printing viscose on textile fabricswhich consists in impregnating the fabric before printing with asolution capable of neutralizin a considerable part of the alkali soona%ter printing and before any material destruction of the cellulose cantake place, drying the impregnated fabric, printing a viscose solutionpreferably containing an excess of alkali and finally fixing the viscoseby steaming, substantially as described.

3. The herein described method of printing viscose on textile fabricswhich consists in impregnating the fabric before printing with asolution of a salt of a volatile base capable of neutralizing aconsiderable part of the alkali soon after printing and before anymaterial destruction of the cellulose can take place, drying theimpregnated fabric, printing with a viscose solution preferablycontaining an excess of alkali and finally] fixing the viscose bysteaming, substantially i as described. 7

4. The herein described method of printl ing viscose on textile fabricswhich consists in impregnating the fabric before rinting with a solutionof a salt of a weak ase capable of neutralizing a considerable part ofthe alkali soon, after printing and before any material destruction ofthe cellulose can take place, drying the impregnated fabric, printingwith a viscose solution preferably containing an excess of alkali andfinally fixing the viscose by steaming, substantially as described.

5. The herein described method of printing viscose on textile fabricswhich'consists in impregnating the fabric before printing with asolution containing ammonium sulfate of such concentration as to becapable of neutralizing a considerable part of the alkali contained inthe viscose solution, drying the impregnated fabric, printing with aviscose solution containing an excess of alkali and finally fixing theviscose by steaming, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EMILE AUGUSTE FOURNEAUX.

\Vitnesses:

SAMUEL WALKEY GILLETI, HERBERT ROWLAND ABBEY.

